Folia Mendeliana: 59/2 (2023) The second issue of this year’s edition of our journal begins with a contribution by Peter van Dijk and T. H. Noel Ellis on G. Mendel’s hitherto unknown journey to Leipzig in 1865. Michael Mielewczik et al. respond to this text in a Letter to the editor. In their second contribution to this issue, the authors date Mendel’s notes in the physics textbook of August von Lichton Kunzek (1795–1865) and identify the remaining textbook Mendel used for his initial homework exercises in meteorology. In their paper on the application of mathematical knowledge in biology classes, Karl Porges et al. address methodological aspects of the use of mathematics in teaching. Gregor Mendel’s research is a classic illustration of the potential for acquiring natural science skills. A more thorough application of mathematical methods in secondary level I and II biology classes leads to a deeper understanding of biological data and supports the interdisciplinary competence of pupils. Other contributions include short reports on The International Mendel Day 2023 – Brno and DNA Day 2023 in the Mendelianum. - Jiří Sekerák
